EDAC/igen6: Convert PCIBIOS_* return codes to errnos

errcmd_enable_error_reporting() uses pci_{read,write}_config_word()
that return PCIBIOS_* codes. The return code is then returned all the
way into the probe function igen6_probe() that returns it as is. The
probe functions, however, should return normal errnos.

Convert PCIBIOS_* returns code using pcibios_err_to_errno() into normal
errno before returning it from errcmd_enable_error_reporting().

Fixes: 10590a9d ("EDAC/igen6: Add EDAC driver for Intel client SoCs using IBECC")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240527132236.13875-2-ilpo.jarvinen@linux.intel.com